Henry c



(No Model.)` l `11.0.]3UGK-- TELEPHONE TRANSMITTER.

No.. 293,561.y Patented Peb. 12, 1884...

IVO

` l livriiiri) -irATns Aram Ormea.

HENRY C. BUCK, OF SOMERVILLE, ASSIGNOR TO FRANCIS M. HOLMES, OF n BOSTON, MASSACHUSETTS.

, TELEPHONE-TRANSIVI ITTER.

SPECIFICATION forming part of LettersPatent No.. 293,561, dated February 12, 1884.

Application tiled June 27, 1881.` (No model.) l

To all whom, t may concern:

Be it known that I, HENRY G. BUCK, of Somerville, in the county of Middlesex and State of Massachusetts, have -invented certain new and useful Improvements in Telephone Transmitters, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, of which-- Figure 1 is a rear elevation; Fig. 2 is a section on line x x, Fig. l. Fig. 3 is a diagram for-illustration.

My invention relates to improvements in telephone-'transmitters' or microphones, in which one electrode is caused to press upon the other by gravity; and it 4consists in mounting one electrode upon a stand or holder, which rests at its lower end upon a base and leans toward the other electrode, the electrode mounted upon the stand resting against the other electrode and pressing against it with a force due to the weight of the holder, but varying with the inclination of the holder from a 1 vertical line. The 'more nearly vertical the holder-that is, the nearer its center of gravity to a vertical plane passing through the points of support of the holder-the less the pressure of the electrode carried by the holder upon the other electrode', and the farther the center of gravity ofthe holder' from this vertical plane the greater the pressure of the electrode carried by the holder upon the` other electrode.

clear at a glance that when the electrode c is carried backwardby the vibration of the diaphragm to the limit indicated by the line y the pressure of the electrode b on electrode c is at the maximum, and that the pressure of b on a decreases as the diaphragm moves from y to z, and increases as the diaphragm moves from z to y. The practical effect of this is to cause the pressure of electrode b on electrode a, and some pressure is essential between the two, to diminish as little as possible the amplitude of the vibrations of the diaphragm.

In the drawings, A is the diaphragm; a., the

electrode fast to the diaphragm; l), the other D, as will be understood without further explanation, so that the circuit is made lthrough wire f diaphragm A, electrodes c b, stand B, base D, and wiref.

I am aware of Patents No. 225,790,.dated March 23, 1880, and No. 234,744, dated November`23, 1880, to E. Berliner, in both of which one electrode is suspended like a pendvlnlum from a point above the other electrode and kept out of a vertical position bycontact` with the lower electrode. I am also aware oi' United States Patent No. 237 ,633, dated February 8, 1881, to E. A. Schoettel, in which the diaphragm is not in the circuit. One end of an inclined arm leans against it and transmits its vibrations to another arm connected to the first. In my transmitter or microphone the diaphragm forms part ofthe circuit, and one of the electrodes islattached to a weighted holder,that rests on a base and is inclined out of the perpendicular and supported by the Velectrode on the diaphragm, so that when the diaphragm vibrates toward the holder it is brought nearer to the perpendicularvand its pressure decreases, and whenit vibrates the other way the pressure increases and assistsA What I claim as my invention s A, provided with an electrode, a, and Wire In 2n telephone-transmitter, the eombndj', substantially as and for the purposes set tion of an electrode, Z), mounted on t stand, forth.

B, constructed substantially as described, a H. C. BUCK. 5 base, D, which supports the stand B, and the XVtnesses:

Wire f', electrically connected with base D, J. E. MAYNADIER,

sta-nd B, and electrode b, with the diaphragm J. R. SNOW. 

